/*
 * Copyright 2024-2024 the original author or authors.
 */

package io.modelcontextprotocol.client;

import java.time.Duration;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;

import io.modelcontextprotocol.client.transport.ServerParameters;
import io.modelcontextprotocol.client.transport.StdioClientTransport;
import io.modelcontextprotocol.spec.McpClientTransport;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.Timeout;
import reactor.core.publisher.Sinks;
import reactor.test.StepVerifier;

import static io.modelcontextprotocol.client.ServerParameterUtils.createServerParameters;
import static io.modelcontextprotocol.util.McpJsonMapperUtils.JSON_MAPPER;
import static org.assertj.core.api.Assertions.assertThat;

/**
 * Tests for the {@link McpSyncClient} with {@link StdioClientTransport}.
 *
 * <p>
 * These tests use npx to download and run the MCP "everything" server locally. The first
 * test execution will download the everything server scripts and cache them locally,
 * which can take more than 15 seconds. Subsequent test runs will use the cached version
 * and execute faster.
 *
 * @author Christian Tzolov
 * @author Dariusz Jędrzejczyk
 */
@Timeout(25) // Giving extra time beyond the client timeout to account for initial server
				// download
class StdioMcpSyncClientTests extends AbstractMcpSyncClientTests {

	@Override
	protected McpClientTransport createMcpTransport() {
		ServerParameters stdioParams = createServerParameters();
		return new StdioClientTransport(stdioParams, JSON_MAPPER);
	}

	@Test
	void customErrorHandlerShouldReceiveErrors() throws InterruptedException {
		CountDownLatch latch = new CountDownLatch(1);
		AtomicReference<String> receivedError = new AtomicReference<>();

		McpClientTransport transport = createMcpTransport();
		StepVerifier.create(transport.connect(msg -> msg)).verifyComplete();

		((StdioClientTransport) transport).setStdErrorHandler(error -> {
			receivedError.set(error);
			latch.countDown();
		});

		String errorMessage = "Test error";
		((StdioClientTransport) transport).getErrorSink().emitNext(errorMessage, Sinks.EmitFailureHandler.FAIL_FAST);

		assertThat(latch.await(5, TimeUnit.SECONDS)).isTrue();

		assertThat(receivedError.get()).isNotNull().isEqualTo(errorMessage);

		StepVerifier.create(transport.closeGracefully()).expectComplete().verify(Duration.ofSeconds(5));
	}

	protected Duration getInitializationTimeout() {
		return Duration.ofSeconds(10);
	}

	@Override
	protected Duration getRequestTimeout() {
		return Duration.ofSeconds(25);
	}

}
